Found this somewhere. Make sense?
If you have the need to run big injectors, lets say 440's buy a GM 3 bar map sensor, wire it into your computer, stick your injectors in, and the car will run perfect.
If you need to add or subtract fuel, hook an Apexi AFC in the mix, and you have fully tunable fuel, and instead of your baseline being -40, your baseline is 0.
How does it work?
Stock injectors are somewhere around 200ml. 440 injectors pump a little over twice as much fuel in all the time. Your map sensor signal strength primarily determines your injector duty cycle. Your stock map sensor is calibrated so that 4.2 volts is 0 psi. The GM 3 bar is calibrated so that 1.6 volts is 0 psi. 1.6 volts, is a little under half of 4.2 volts. What this means is that the GM sensor sends out a low ball output to the ECU, and the ecu cuts the injector duty cycle in half, making the car run perfect.
For all who are running the afc hack and want to see your fuel curve so that it isn't way off the scale, on your Apexi, goto ETC. > Sensor type, set Out to 14 and keep your input at 06. Set your -40's to 0's and your car will run just right.
The sensor number 06 is the code for the stock honda map sensor, and the sensor number 14 is the closest you'll get to the GM 3 Bar setting. Say you want to run stock injectors with a GM 3 bar map sensor, set your input to 14, and your out to 06, and the AFC will automatically convert your GM map sensor signal to a Honda Map signal, and then you can tune your fuel curve.
On my car, I'm currently running the GM 3 bar sensor, My Apexi Sensor settings are 14 input, and 14 output. This means GM in, GM out. The GM out compensates for the big injectors and sets my fuel adjustment baseline at zero. Since I'm not running a missing link device I just lean my curve under wide throttle to -7% from 3500-9000. That has worked so far with 15 lbs of boost. I'm running an FMU because I would need rediculously large injectors to run stock rail pressure on 15 lbs. of boost. The setup works great, however I do get the occassional bog between 2 and 3 grand, but I'm working on a solution to that at the moment. If you have any questions, let me know. I have spent great deals of class time researching and a great deal of time almost getting in wrecks trying to figure this apexi out.
Power Curve
